1. Field of the Invention
The present invention relates, generally, to apparatus and methods for implanting objects beneath membranes. More particularly, the invention relates to implanters for depositing electronic tracing devices, hormone pellets or other objects or pellets beneath a membrane.
2. Background Information
The state of the art in general includes various devices and methods for implanting objects beneath a membrane using a device that has a rod which travels through a hollow needle to deposit the object through the needle and beneath the punctured membrane. For example, the objects or pellets may comprise electronic tracing devices or transponders which are used to tag an animal, or the pellets may comprise hormone pellets which are used in the domestic livestock fattening industry to promote growth of the animal. The pellets are often injected into the ears of the animals to prevent the pellets from entering food products for human or animal consumption as the ears are commonly discarded in slaughtering. Typically, the ear is grabbed with one hand while the other hand operates the implanter. The pellets should be carefully, properly and accurately implanted to reduce the probability for infection and increase the effectiveness of the deposited pellets. Further, because of the movements of the animals, it is desirable for the pellets to be quickly implanted into the animal.
These devices and methods are believed to have significant limitations and shortcomings. One of the shortcomings is that implanter devices may spread blood-borne diseases among the animals if the needle is not replaced for each animal. In recognition of this problem, Turley (U.S. Pat. No. 5,279,554) disclosed a device that uses a shroud or covering that moves and locks in an extended position to partially cover the needle, and thus encourages a user to replace the needle after each use. Another shortcoming of the known art is the inability to automatically, quickly, consistently and powerfully implant multiple pellets. Turley (U.S. Pat. No. 4,154,239) disclosed that the link between the drive pin and the trigger actuator in the known art devices tended to buckle, and further disclosed that the speed or velocity of the drive pin was limited because the known art devices employed a 1:1 ratio between the drive pin and the trigger/actuator. In recognition of these problems, Turley ('231) disclosed a device that uses a flexible belt or link to achieve a velocity ratio other than 1:1. Other devices have achieved a velocity ratio other than 1:1 by attaching spur gears to the trigger and a rack gear to the drive pin.
Applicants' invention provide an implanter apparatus which is believed to constitute an improvement over existing technology.